根据下面资料，回答题
I′ve often wondered how exactly sleep, or lack of it, can have such an awful effect on our bodies and, guess what, how much we sleep switches good genes on and bad genes off.
In the first half of 2013, the Sleep Research Centre at the University of Surrey found a direct link between hours spent sleeping and genes. Every cell in our bodies carries genetic instructions in our DNA that act as a kind of operating handbook. However, each cell only "reads" the part of this handbook it needs at any given moment.
Can sleep affect how a gene reads instructions It′s a question asked by Professor Derk-Jan Dijk at the University of Surrey. He set up an experiment and asked his volunteers to spend a week sleeping around seven and a half hours to eight hours a night and the next sleeping six and a half to seven hours.
Blood samples were taken each week to compare which genes in blood cells were being used during the long and short nights. The results were rather surprising. Several hundred genes changed in the amount they were being used, including some that are linked to heart disease, cancer, and Type 2 diabetes. Genes to do with cell repair and replacement were used much less.
Sleep restriction (six and a half to seven hours a night) changed 380 genes. Of these,220 genes were down regulated (their power was reduced), while 160 were up regulated (their power was increased). Those affected included body-clock genes which are linked to diabetes. One of the most downgraded genes is that which has a role in controlling insulin and is linked to diabetes and insomnia. The most upgraded gene is linked to heart disease.
So changing sleep by tiny amounts can upgrade or downgrade genes that can influence our health and the diseases we suffer from when we sleep too little.
The important message is that getting close to eight hours of sleep a night can make a dramatic difference to our health in just a few days through the way it looks after our genes.
What kind of relation is directly discussed in the passage 查看材料
主旨题。阅读第一段、最后一段和每段第一句话，不难看出本文主要讲的是睡眠时间与人体内基因的关系。第二段中的“a direct link between hours spent sleeping and genes”更是直接地进行了表述。故选A。
“有为才有位，有位更有为”，这一看法给我们的启示是（ ）
对立统一规律揭示了事物发展的( )。
历史唯物主义认为人的价值在于（ ）
在认识过程中具有更为重要意义的飞跃是指（）
矛盾的普遍性与特殊性的关系是（ ）
毛泽东第一次提出“马克思列宁主义理论和中国革命的实践相结合”这个根本思想原则的著作是（ ）
真理的具体性体现在( )。
“没有抽象的真理，真理总是具体的。”这一思想可以理解为( )。
毛泽东在( )这篇文章中提出了“没有调查，就没有发言权”的著名论断。
“三个代表”重要思想是马克思主义中国化的最新理论成果。它与马克思列宁主义、毛泽东思想、邓小平理论是一脉相承的统一的科学理论。这种一脉相承具体表现在（ ）
